Hi,I am making a small RGB LED light, controlled by Arduino. I have it connected to a 5-8 V powersupply. I noticed that, when the light is turned off, it still uses 3-4 W. I therefore measured the current through the Arduino which was 160 mA, even when I disconnected all buttons, mosfets, etc. Then I though that the sketch might perhaps use to much current, but when I upload the most simplest of all sketched (blink, without led usage), it still uses 160mA.

Is this the standard consumption of the Arduino? I haven't come across any reference to this and it appeard to me quite a bit. Any suggestions to lower the power consumption by the Arduino?

That sounds quite high. I just measured by Arduino Uno, and it only measured about 50mA (which is about what I'd expect. There are graphs in the AVR datasheets that show they should be around 20mA when running at 16MHz, and there are two of them, plus some other relatively low-current devices.)

I have an Arduino Duemilanove with the ATmega328p processor. When I attach a stabilised 5V to the 5V pin, it draws 132 mA. When I connect 5V to the Vin pin, it draws 108mA. Increasing the voltage to the Vin results in the following current±

5V 108 mA6V 140 mA6.5V 153 mA7V 161 mA8.4V 161 mA

I need to use the 8.4V, since my RGB LED draws a lot of current, resulting in a voltage drop. Lower voltage would be to low for the Arduino.

When I removed the ATmega328 , the current was only 9 mA (at 5V on 5V pin and 7 and 8.4V on Vin pin). Therefore I placed two other ATmega328's I have laying around. Both measure around 26 mA at the three voltages.

Clearly it is the ATmega328, but do you have any idea how come it differs from the others??